Albert schmidt



AQSCHMIDT. SPARK PLUG.

APPLICATION FILED MAR.8.19|7.

1,319,423. Patented oct. 21,1919.

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UNITED sTATEs PATENT oEEICE. f

ALBERT SCHMIDT, 0E FLINT, MICHIGAN, AssIGNoR. To CHAMPION IGNITION COMPANY,

or ELINT, MICHIGAN, A CORPORATION 0E MICHIGAN.

SPARK-PLUG.

Specification of Letters Patent.

Patented oct. 21, 191.9.

Application led March 8, 191.7. i Serial No. 153,234,

- of Michigan, have invented certain new and Vuseful Improvements In Spark-Plugs, of

whichthe following is a specication, reference being had therein to the accompanying drawings.

The invention relates to spark-plugs, and has more' particu-lar reference to the means of attaching the grounded electrode to ,the`

plug casing. In the present state `of the art it is usual t-o form the plug lcasings with a threaded nipple for engagement with the engine casing `and to` attach the electrode thereto by drilling into the end of the cylin* drical shell of the nipple and inserting a wire electrode therein. The operation of vdrilling is one requiring considerable timel with the frequent breaking of drills, and

vweld. 'lf V- A is the spark-plug casing, which is pro-` after the holes have been formed the electrodesmust' be engaged therewith 4and secured to form both an electrical and mechanical joint. Thus the cost.A of attaching the 'electrode is a considerable item.

With the pre'sent construction I have dis pensed with the necessity o f drilling-and have obtained a better mechanical and electrical connection, byD electrically welding the inner end of the electrode to the casing shell.

In the drawings:

v Figure 1 is a perspective view of the com- `pleted structure;

Fig. 2 is a section showing the manner of forming the weld; and

Fig. 3 is a similar' view of the completed vided with a polygonal section B and a threaded nipple section C. at `the inner end thereof. This nipple section is in the form f of a cylindrical shell having comparatively thin walls. shown is in the form of a wire'of-'round cross-section, but which may be of any suitwith a segment of thenipple shell, as shown in Fig. 2, and engaged with the electrodes of a suitable welding apparatus bywhich D is the electrode, which as f conducting joint.

at E Fig. 2. The process by which this'is accomplished is not, however, part of the present inventionand therefore will not be described in detail.

In forming theV welded-joint as justmde I scribed, the inner end portion of the elec-- trode will be slightly upset or enlarged, due

to fusion and pressure, as indicated at F, thereby forming a strong mechanical and good electrical connection. Also by thus integrating the metal of the electrode with that of the casing the heat of the electrode is more rapidly dissipated, which insures a longer life.

What I claim asmy invention is:

1. The combination with a cylindrical shell, of a metallic member projecting from said shell and having its inner end butt` welded thereto.

2. The 'combination with a cylindrical shellof asparlI-plug casing,.of an electrode projecting from a` segment of said shell havv ing its inner end butt-welded thereto.

The combination with. a spark-plug casing rhaving a threaded nipple terminating in a comparatively thin-.walled shell, of an electrodebutted against the thin Wall of saidshell and welded thereto.

4. The Icombination with a spark-plug y casing having a threaded nipple terminating in a comparatively thin-walled shell; of an electrode butted againstsaid'shell and welded thereto, the. welded end being slightly upset and enlarged to form a irmmechanical and a good electrical-and heat- 5.. 'The combination with aspark-plug cas1ng',-of an electrode welded vto said casing and molecularly integrated therewith to formvhigh thermal ity therebetween.v

and electrical conductivs ALBERT SCHMIDT.

In testimony whereof I vaiix my signature. f 

